1. Field of the Invention
The present invention relates generally to a boiler apparatus or other fluid heating apparatus, and to a housing for containing and supporting a boiler. The present invention also relates to a door for providing access to a boiler located in a confined location. The present invention also relates to a method of operating and/or maintaining a boiler apparatus.
2. Description of the Related Art
Known boilers (fluid heating devices) use various combustion processes which produce flue products consisting of water vapor, carbon dioxide, unburned fuel, oxidized contaminants, carbon and other particulate material which may and do adhere to the heat transfer surfaces. These surfaces are designed to absorb the heat of combustion as much as possible before the heat exits the boiler into the vent system.
Periodic inspection and cleaning of boiler heat exchange surfaces may be required to insure optimum heat transfer performance. Such maintenance may also be needed to insure that flow passages are free and open so as not to restrict the flow of combustion products. Such obstructions could create back pressure at the burner and reduce proper fuel balance resulting in subsequently less clean burning and increased surface contamination and restriction. There is thus a need in the art for a boiler apparatus that provides optimum heat transfer surface contact for efficient transfer as well as access to the heat transfer surfaces to permit inspection and complete and thorough cleaning when required.
A known boiler that provides efficient heat transfer is described in U.S. Pat. No. 4,261,299. The known boiler has an insulated back cover. The cover may be removed to provide access to the interior heat exchange surfaces for maintenance and repair. Obtaining access to the back cover, which is opposite to the front of the boiler (and opposite the burner and controls), requires a clearance space of at least twelve inches (and preferably twenty-four to thirty inches for easier servicing). The known apparatus has significant space requirements.
Other known boilers, which vary significantly in design of combustion, heat transfer and flue passages, have removable cleanout panels on the top, sides, back or front. Recently, it has been proposed to mount the burner on a hinged door which could swing to either the right or the left (horizontally) to allow access to passages without physical removal and setting the cover aside. A disadvantage associated with the proposed arrangement, however, is that when the door swings to the side, the burner and the cover require a relatively large side access area. The need for side access space may preclude use of the door. In certain confined locations, the door may have to be removed from the housing to gain access to the boiler for inspection and cleaning.
Conventional boilers, due to their heavy weight, are normally mounted on or near the floor. This is a disadvantage because it makes it difficult to service them. The repair technician must be seated on the floor or bent over in an awkward position with poor or incomplete visibility of the passages that need to be inspected or cleaned.
Prior art heating devices are shown in U.S. Pat. Nos. 787,617 (Evans); 1,416,487 (Mauck); 2,200,304 (Sands); 2,237,054 (Jensen); 2,562,023 (Dufault); 3,151,615 (Siniaho); 3,934,554 (Carlson); 4,418,649 (Purvis); and 4,872,443 (Ruark).